The latest Israeli offensive is again targeting key roads and bridges. Meanwhile, British Prime Minister Tony Blair delayed the start of his holiday Friday to work on a U.N. cease-fire for Lebanon.

Officials in Israel say Hezbollah fired more than 40 rockets at Israel Friday. An Israeli police force showed off some remnants of those rockets, which one Israeli police official said were made in Syria.

Israeli warplanes continue to pound southern Beirut and bridges leading north from the capital in the country's Christian heartland.

Israeli jets also bombed several villages in southern Lebanon, including suspected Hezbollah targets in the city of Tyre.

Israeli ground troops were seen Friday crossing into southern Lebanon and back into Israel. Israeli Major-General Beni Ganz says Israel will use whatever force is necessary to achieve its goal of making Hezbollah unable to threaten his country.

Meanwhile, the United Nations representative in Lebanon, Geir Perderson, once again called for a complete cease-fire. "The Secretary General strongly believes that we should have a cessation of hostilities immediately. It should happen today. Too many innocent people have been killed, too many civilians, and there is no excuse anymore not to stop the fighting."

The U.N. also said that its aid organizations will help the Lebanese government start a mass immunization campaign to prevent an outbreak of potentially fatal measles among refugee children. A UNICEF representative in Lebanon said children aged five and under will also be immunized against polio, a highly contagious disease that can lead to paralysis or death.